This is against the scsi-bidi tree. We need to use the cmd_type of a leading request for scsi_init_sgtable to set up scsi_data_buffer:length of a bidi request properly. An alternative approach is setting the cmd_type of a leading request and its bidi request (*1). But the block layer and scsi-ml don't expect that the leading request and its sub-requests have the different command types. Note that scsi_debug's XDWRITEREAD_10 support is fine without this patch since req->nr_sectors works for it but req->nr_sectors doesn't work for everyone. (*1) http://www.mail-archive.com/linux-scsi@xxxxxxxxxxxxxxx/msg12669.html = From: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Subject: [PATCH] use the cmd_type of a leading request for scsi_init_sgtable We need to use the cmd_type of a leading request for scsi_init_sgtable to set up scsi_data_buffer:length of its bidi request properly. Signed-off-by: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> --- drivers/scsi/scsi_lib.c | 23 ++++++++++++++--------- 1 files changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index e1c7eeb..61093ea 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1001,8 +1001,9 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) scsi_end_request(cmd, -EIO, this_count, !result); } -static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, - gfp_t gfp_mask) +static int scsi_init_sgtable(struct request *req, + enum rq_cmd_type_bits cmd_type, + struct scsi_data_buffer *sdb, gfp_t gfp_mask) { int count; @@ -1015,12 +1016,12 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, } req->buffer = NULL; - if (blk_pc_request(req)) + if (cmd_type == REQ_TYPE_BLOCK_PC) sdb->length = req->data_len; else sdb->length = req->nr_sectors << 9; - /* + /* * Next, walk the list, and fill in the addresses and sizes of * each segment. */ @@ -1043,21 +1044,25 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb, */ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) { - int error = scsi_init_sgtable(cmd->request, &cmd->sdb, gfp_mask); + int error; + enum rq_cmd_type_bits cmd_type = cmd->request->cmd_type; + + error = scsi_init_sgtable(cmd->request, cmd_type, &cmd->sdb, gfp_mask); if (error) goto err_exit; if (blk_bidi_rq(cmd->request)) { - struct scsi_data_buffer *bidi_sdb = kmem_cache_zalloc( - scsi_bidi_sdb_cache, GFP_ATOMIC); + struct scsi_data_buffer *bidi_sdb; + + bidi_sdb = kmem_cache_zalloc(scsi_bidi_sdb_cache, GFP_ATOMIC); if (!bidi_sdb) { error = BLKPREP_DEFER; goto err_exit; } cmd->request->next_rq->special = bidi_sdb; - error = scsi_init_sgtable(cmd->request->next_rq, bidi_sdb, - GFP_ATOMIC); + error = scsi_init_sgtable(cmd->request->next_rq, cmd_type, + bidi_sdb, GFP_ATOMIC); if (error) goto err_exit; } -- 1.5.3.4 - To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
